Method of buffing the edges of metal fasteners



Nov. 19, 1940. sMn-HE ET AL 2,221,885

METHOD OF BUFFING THE EDGES OF METAL FASTENERS Filed Jan. 27, 1937 2 Sheets-Sheet 1.

Q N I Q z x k M'Vf/WOEJ flank 6. dm 21776 Abraham Nov/ck ATTOiQNEYS NOV. 19, F B sMlTHE E AL METHOD OF BUFFING THE EDGES OF METAL FASTENERS Filed Jan. 27, 1937 2 Sheets-Sheet 2 AVVf/VTOPJ frank 6. J/mZ/ge Abraham N0 v/c/r 'ATTO R N EYS Patented Nov. 19, 1940 UNITED STATES PATENT OFFICE lWETHOD OF BUFFING THE EDGES OF BIETAL FASTENERS Frank B. Smithe, Douglaston, and Abraham Novick, Flushing, N. Y., assignors to F. L.

Smithe Machine 00.,

Inc., New York, N. Y., a

7 Claims.

This invention relates to the fabrication of metal fasteners, especially to fasteners of the type adapted to be affixed to a rear wall of an envelope below an apertured closure flap, and having tongues to be bent up into position to protrude through the aperture in the flap, and then to be bent back into retentive position over the opposite margins of the aperture.

The" invention is more particularly concerned with the step of finishing the fasteners while assembled in conventional stack formation as they are sold to envelope manufacturers for application to the envelopes, this finishing step being effective to remove from the edges of the tongues the burr formed thereon in the course of die-cutting or stamping the fasteners bodily from sheet metal.

While this burr may be of slight proportions and not of serious import apparently, it has been found to have sufficient abrasive effect upon the fingers of an operative charged with the duty of bending up a large quantity of the tongues in the course of loading such envelopes, to wear away the cuticle uncomfortably and even dangerously in the course of a single day.

Under such conditions, it is the general object of the present invention to provide an effective method of reducing this objectionable burr to an extent which deprives it of its abrasive characteristic, and a particular object is to accomplish this burr-reduction as a finishing operation performed continuously upon a large number of the fastener blanks assembled upon the conventional U-shaped wire holder disclosed in U. S. Letters Patent No. 1,827,901, and it may be the final step in the fabrication of the fasteners preparatory to furnishing each such sales unit to a user.

Another object of the invention is to provide means to facilitate the presentation of the aforesaid stacks of fastener blanks for a buffing operation to reduce the burrs effectively with a minimum of effort and skill upon the part of an operative, and at low cost for the operation; also with optimum accuracy, and without displacing any of the fastener blanks from its relative order in the stack.

Other objects and advantages of the invention will appear as the description of the particular physical embodiment selected for illustration and description progresses.

In the accompanying drawings, like characters of reference have been applied to corresponding parts throughout the several views which make up the drawings, in which:

Fig- 1 is a view of a schematic character illustrating a buffing means for carrying into effect the method of the present invention;

Fig. 2 is a transverse sectional view of a similar character, showing the parts of Fig. 1 in their operative relationship;

Fig. 3 is a fragmentary detail view of several of the assembled fastener blanks, with their tongues in their proper ofiset position for burrremoval;

Fig. 4 is a view similar to Fig. l of a modification of the means for carrying the present invention into effect;

Fig. 5 is a vertical sectional view taken on the line 5-5 of Fig. 4;

Fig. 6 is a view similar to Figs. 1 and 4, of still another modification of the means for carrying the present invention into effect;

Fig. '7 is a vertical sectional elevation on the line 1-1 of Fig. 6.

In one embodiment of means for carrying the present invention into effect, a couple of buffing wheels B, B of suitable material are caused to rotate about axes H and [2, the working planes of these buffing wheels being offset from each other and from a median vertical plane y-y. (See Fig. 2), which defines a path along which a conventional stack of fastener blanks, designated generally by the reference character S is fed lengthwise in the direction of the arrow l3, with a twisting movement.

Such a stack may desirably be of the form illustrated in my U. S. Letters Patent 1,827,901, granted October 20, 1931, to which reference may be had for a more complete description than it is necessary to include herein; and for the purposes of the present disclosure it will be suflicient to point out the general contour and disposition of the fastener blank components M, which are assembled with their broad faces l5 in contact to make up the stack.

Each fastener blank 14 is formed of thin metal, and as is evident from an inspection of the drawings, the blanks are cross-shaped so that opposed re-entrant angles occur at the junctions of the body portions 2 and 3 with the arms 4 and 5.

For the purpose of maintaining a multiplicity of these blanks in orderly assembled relationship for shipment to envelope factories, and for handling in such factories, provision is made of a staple-like member 6 having parallel legs I and 8 50 thereof disposed in opposite re-entrant angles of the blank stack so as to embrace and interfit with the blanks.

This staple-like holding member 6 may be of considerable length, and the legs I and 8 are 5 bendable to a limited extent; extending beyond the stack where provision is made of a holding plate 9 and a locking plate I0, both of which are impaled upon the said projecting portions to maintain the stack against separation from, or disarrangement relatively to, the holding member 6, all as described in said patent.

In the operation of stamping out such fastener blanks from sheet metal stock, a slight burr or rugosity is developed, and remains, around one complete edge, and the object of the present invention is to relieve the tongues or arms 4 and 5 from this undesirable burr, as at the edges 4x and 5:: respectively; so that the invention provides for such disposition of the stacked blanks that the edges 42: and 5:1: are presented in salient position for the action thereon of the buffing or finishing wheels, as the stack of blanks is advanced past the finishing station.

Such salient presentment may be effected in any suitable Way, and as one suitable mode of providing therefor, the entire stack S with its staple 6 may be given a spiral turn around its mean longitudinal axis, as illustrated in Fig. l, with'the effect that each of the edges of the components 4 and 5 will be so turned that, as appears clearly from Fig. 3 and Fig. 2, the bufiing wheel B will encounter a series of the stepped flange edges 5:: as it rotates, and the bufiing wheel 3' will simultaneously encounter a series of the stepped flanges 4x, acting to buff off and relieve the objectionable burr as desired.

When one edge has thus been relieved, the step may be repeated by twisting the stack to form a spiral in the opposite sense, and passing the stack again between the buffers .B and B, uniformity of action being promoted by the use of guides I6 and II, respectively. After both sides have been thus finished, the staple holder is twisted back to a Straight condition.

In a modified embodiment of means to carry the invention into effect, as illustrated in Figs.- 4 and 5, the presentation at the finishing stage F of the blanks I4, assembled upon a U-shaped staple or holder 61', as in the aforesaid'arrangement of Patent No. 1,827,901, is effected while the wire legs I and 8 of the holder retain the straight disposition in which they come from the operation of assembling the blanks I4 in stack form on the staple, and in which straight disposition it is desirable to have them remain after finishing, for storage, transportation and use.

The method of treatment according to the modification illustrated in Figs. 4 and 5 provides for finishing treatment by a pair of buffer wheels B and B which are arranged in the same vertical plane as that occupied by the tongues or arms 4 and 5 (see Fig. 5), of the blanks I4, as the stack S is advanced bodily from right to left. The leading end of the stack is supported by a, guide Him and the bodily advancement of the stack is accomplished by means of a screw 34 rotatable in a head H by suitable means (not shown).

At the time of original assembly of the-blanks in stack form upon the staple 6x, or thereafter prior to the finishing step, the end retaining members 9 and III are set in such a position as to leave space for a certain amount of play of the blanks within the limits of the stack, and the efiect .is toafford room for each blank to be biased individually away from the contiguous succeeding blank in the direction of bodily feeding movement of the stack, from right to left in the present instance. I I

This starts with the first stack component, as

I41: (see Fig. 4), at the time that the left-hand end of the stack passes into the finishing station F and in order that only one blank I4 may be permitted to emerge into finishing position at a time, spring friction devices N, N are preferably provided, in conjunction with a pair of guides 33 through which the stack S is lead for treatment.

The friction device includes a pair of spring fingers EM and 32, each fixed upon the trough-like guide member 33 mounted on a. suitable support (not shown) and which serve as guides for the stack.

As the latter is advanced, by rotation of the screw 34 in the head H, one blank at a time is pressed forward through the fingers 3| and 32 and released for the action of the bufilng rolls, which cause it to spring across the gap G, and its rugous edges E are thereby exposed for bufilng.

In another embodiment of the invention, illustrated in Figs. 6 and '7 of the drawings, a stack S, comprising a multiplicity of blanks I4 assembled upon a staple or holder 66 substantially as disclosed in U. S. Letters Patent No. 1,827,901, is presented for finishing at a station F", as by a pair of buffing wheels B and B the stack of blanks being fed bodily past the station from right to left, by suitable mechanism, not shown.

The lower edges E of the closely assembled blanks I4 composing the stack rest upon a ledge or templet L and are caused to travel in succession over a. shoulder C which is so disposed with relation to the bufiing wheel B that as the latter is rotated counter-clockwise against the exposed upper edges E of the blanks (see Fig. '7), the wheel exerts a downward bias against the blanks which become effective to displace transversely of the stack each successive blank when its lower edge is fed past the shoulder C. This displace-.

ment of each blank is permitted by the nature of the support of the blanks on the staple 66, the elements I and 8 allowing such displacement of individual blanks to the extent indicated by virtue of the slight looseness of the fasteners on the staple, and as the displacement occurs, the leading edge E" of the contiguous undisplaced blank is then exposed to the finishing action of the bufiing which is effective to remove the residual burrs or rugosities left by the dies at the time of stamping out the blanks.

When the stack has been fed completely past the finishing station, and the edges E and E of all of the blanks have been thereby finished, the stack will be then replaced bodily at the starting point in reversed position, top for bottom, and fed through again, for the purpose of finishing the edges E.

From the foregoing, it will be evident that in the operation of the several embodiments of means for carrying the invention into efi'ect, there is involved, in each of these, the step of feeding bodily past a finishing station, as F, in Figs. 1-3, or F as in Figs. 4 and 5, or F in Figs. 6 and 7, a stack of blanks I4 assembled upon a staple or holder, as 6, 6a: or 66, so that the bufilng wheels or like finishing members as B, B, B", B and B B in each instance, act upon one or more edges of the blanks I4, as E, E', E", etc., to perform the step of removing therefrom the characteristic burrs or rugosities which remain after a die-cutting or stamping operation.

While this removal of a burr fromthe edges of the fastening tongues or arms 4 and 5 of metal envelope fasteners is the intended use illustrated by way of example, it will be apparent that the invention is capable of application in the continuous finishing, as by polishing or otherwise treating of many different kinds of articles of which a multiplicity may be assembled in stack form.

Furthermore, the several modes of presenting the articles individually for treatment, while preserving their relative order in their stacks, as by twisting the stack according to the mode shown in Figs. 1, 2 and 3; that by creating a gap in the stack, so that each blank is exposed completely as at G in the form shown in Figs. 4 and 5; and the mode shown in Figs. 6 and 7 according to which a relatively small sidewise displacement of each blank in turn exposes the edge, as E of a contiguous blank for treatment; are merely illustrative physical embodiments of the idea of means underlying the invention, and indicate the flexibility of the novel method, which may be carried into effect by many other modifications of the means illustrated, these not exhausting the possible physical embodiments of such underlying idea of means.

We have described what we believe to'be the best embodiments of our invention. We do not wish, however, to be confined to the embodiments shown, but what we desire to cover by Letters Patent is set forth in the appended claims.

We claim:

1. The continuous method of relieving a multiplicity of stamped sheet metal articles having identical contour and size, while assembled in stack form, of edge burrs or rugosities remaining from said stamping operation, said method including the step of twisting the stack bodily to dispose each article in a position in said stack where its rough edge is exposed relatively to the corresponding edge of a succeeding article, the step of bufling in turn each rough edge so exposed, and the step of advancing the stack bodily past the bufiing station.

2. The method as claimed in claim 1, in which the stack is twisted to form the articles into a spiral in the opposite sense in order topresent other edges of the articles in like position for finishing, and the bufiing step is repeated while the stack is again advanced bodily past the bufiing station.

3. The continuous method of finishing a multiplicity of die-cut sheet metal articles having identical contour and size, while assembled in stack form upon a U-shaped holder to remove edge burrs or rugosities remaining from said diecutting operation, said method including the step of twisting the legs of the U-shaped holder relatively to each other, thereby deforming the stack bodily to dispose each article in a position in said stack where its cut edge is exposed relatively to a succeeding article, the step of buffing in turn each cut-edge so exposed, and the step of advancing the stack and U-shaped holder bodily past the buifing station.

4. The continuous method of finishing a multiplicity of die-cut sheet metal articles having identical contour and size, while assembled in stack form, upon a U-shaped holder, to remove edge burrs or rugosities remaining from said diecutting operation, said method including the step of twisting the legs of the U-shaped holder relatively to each other, thereby deforming the stack bodily to dispose each article in a position in said stack where its out edge is exposed relatively to a succeeding article and the step of feeding the entire stack bodily past a buffing station while rotating the stack to feed the individual edges to be finished in a helical path defined by the twist imparted to said holder.

5. Fhe method as claimed in claim 4, in which the last-named step is repeated in an order adapted to present other edges in like position for finishing.

6. The method of relieving the edges of stamped sheet metal articles having oppositely disposed arms extending from a central body portion and of identical contour and size, of edge burrs remaining from the stamping operation, said method including the step of retaining the articles, while in stack form, with the arms of contiguous articles disposed at successively higher levels, the step of bufiing the upper edge of an arm of each article and the lower edge of its opposite arm and the. step of advancing the stack bodily past the bufiing station.

'7. The method as claimed in claim 6 in which the edges of the arms of each article are buffed simultaneously.

FRANK B. SMITHE. ABRAHAM NOVICK. 

